Flooding in the Midwestern U.S. has collapsed a railroad bridge and is testing a dam after days of heavy rains that have forced hundreds of people to evacuate or be rescued. The flooding brought additional misery to parts of Iowa, Nebraska, South Dakota and Minnesota as temperatures approached 100 degrees Monday. More rain is forecast, and many streams may not crest until later this week as the floodwaters slowly drain. Governors of the affected states say the flooding has damaged roads and bridges, shuttered or destroyed businesses, required hospitals and nursing homes to evacuate, and left cities without power or drinking water.